1 /*
2 * Copyright (c) 2017 Linaro Limited
3 * Copyright (c) 2016 Nordic Semiconductor ASA
4 * Copyright (c) 2015-2016 Intel Corporation
5 *
6 * SPDX-License-Identifier: Apache-2.0
7 */
8
9 #include <errno.h>
10 #include <stddef.h>
11 #include <stdio.h>
12
13 #include <zephyr/kernel.h>
14 #include <zephyr/sys/byteorder.h>
15 #include <zephyr/logging/log.h>
16 #include <zephyr/debug/stack.h>
17
18 #include <zephyr/device.h>
19 #include <zephyr/init.h>
20 #include <zephyr/drivers/gpio.h>
21 #include <zephyr/drivers/spi.h>
22
23 #include <zephyr/net/buf.h>
24 #include <zephyr/bluetooth/bluetooth.h>
25 #include <zephyr/bluetooth/l2cap.h>
26 #include <zephyr/bluetooth/hci.h>
27 #include <zephyr/bluetooth/buf.h>
28 #include <zephyr/bluetooth/hci_raw.h>
29
30 #define LOG_MODULE_NAME hci_spi
31 LOG_MODULE_REGISTER(LOG_MODULE_NAME);
32
33 #define HCI_CMD 0x01
34 #define HCI_ACL 0x02
35 #define HCI_SCO 0x03
36 #define HCI_EVT 0x04
37
38 /* Special Values */
39 #define SPI_WRITE 0x0A
40 #define SPI_READ 0x0B
41 #define READY_NOW 0x02
42 #define SANITY_CHECK 0x02
43
44 /* Offsets */
45 #define STATUS_HEADER_READY 0
46 #define STATUS_HEADER_TOREAD 3
47
48 #define PACKET_TYPE 0
49 #define EVT_BLUE_INITIALIZED 0x01
50
51 /* Needs to be aligned with the SPI master buffer size */
52 #define SPI_MAX_MSG_LEN 255
53
54 static uint8_t rxmsg[SPI_MAX_MSG_LEN];
55 static struct spi_buf rx;
56 const static struct spi_buf_set rx_bufs = {
57 .buffers = &rx,
58 .count = 1,
59 };
60
61 static uint8_t txmsg[SPI_MAX_MSG_LEN];
62 static struct spi_buf tx;
63 const static struct spi_buf_set tx_bufs = {
64 .buffers = &tx,
65 .count = 1,
66 };
67
68 /* HCI buffer pools */
69 #define CMD_BUF_SIZE BT_BUF_RX_SIZE
70
71 /*
72 * This finds an arbitrary node with compatible
73 * "zephyr,bt-hci-spi-slave". There should just be one in the
74 * devicetree.
75 *
76 * If for some reason you have more than one of these in your
77 * devicetree, replace this macro definition to pick one, e.g. using
78 * DT_NODELABEL().
79 */
80 #define HCI_SPI_NODE DT_COMPAT_GET_ANY_STATUS_OKAY(zephyr_bt_hci_spi_slave)
81
82 /*
83 * This is the SPI bus controller device used to exchange data with
84 * the SPI-based BT controller.
85 */
86 static const struct device *const spi_hci_dev = DEVICE_DT_GET(DT_BUS(HCI_SPI_NODE));
87 static struct spi_config spi_cfg = {
88 .operation = SPI_WORD_SET(8) | SPI_OP_MODE_SLAVE,
89 };
90
91 /*
92 * The GPIO used to send interrupts to the host,
93 * configured in the 'irq-gpios' property in HCI_SPI_NODE.
94 */
95 static const struct gpio_dt_spec irq = GPIO_DT_SPEC_GET(HCI_SPI_NODE, irq_gpios);
96
97 static K_THREAD_STACK_DEFINE(bt_tx_thread_stack, CONFIG_BT_HCI_TX_STACK_SIZE);
98 static struct k_thread bt_tx_thread_data;
99
100 static K_SEM_DEFINE(sem_spi_rx, 0, 1);
101 static K_SEM_DEFINE(sem_spi_tx, 0, 1);
102
spi_send(struct net_buf * buf)103 static inline int spi_send(struct net_buf *buf)
104 {
105 uint8_t header_master[5] = { 0 };
106 uint8_t header_slave[5] = { READY_NOW, SANITY_CHECK,
107 0x00, 0x00, 0x00 };
108 int ret;
109
110 LOG_DBG("buf %p type %u len %u", buf, bt_buf_get_type(buf), buf->len);
111
112 switch (bt_buf_get_type(buf)) {
113 case BT_BUF_ACL_IN:
114 net_buf_push_u8(buf, HCI_ACL);
115 break;
116 case BT_BUF_EVT:
117 net_buf_push_u8(buf, HCI_EVT);
118 break;
119 default:
120 LOG_ERR("Unknown type %u", bt_buf_get_type(buf));
121 net_buf_unref(buf);
122 return -EINVAL;
123 }
124
125 if (buf->len > SPI_MAX_MSG_LEN) {
126 LOG_ERR("TX message too long");
127 net_buf_unref(buf);
128 return -EINVAL;
129 }
130 header_slave[STATUS_HEADER_TOREAD] = buf->len;
131
132 gpio_pin_set(irq.port, irq.pin, 1);
133
134 /* Coordinate transfer lock with the spi rx thread */
135 k_sem_take(&sem_spi_tx, K_FOREVER);
136
137 tx.buf = header_slave;
138 tx.len = 5;
139 rx.buf = header_master;
140 rx.len = 5;
141 do {
142 ret = spi_transceive(spi_hci_dev, &spi_cfg, &tx_bufs, &rx_bufs);
143 if (ret < 0) {
144 LOG_ERR("SPI transceive error: %d", ret);
145 }
146 } while (header_master[STATUS_HEADER_READY] != SPI_READ);
147
148 tx.buf = buf->data;
149 tx.len = buf->len;
150
151 ret = spi_write(spi_hci_dev, &spi_cfg, &tx_bufs);
152 if (ret < 0) {
153 LOG_ERR("SPI transceive error: %d", ret);
154 }
155 net_buf_unref(buf);
156
157 gpio_pin_set(irq.port, irq.pin, 0);
158 k_sem_give(&sem_spi_rx);
159
160 return 0;
161 }
162
bt_tx_thread(void * p1,void * p2,void * p3)163 static void bt_tx_thread(void *p1, void *p2, void *p3)
164 {
165 uint8_t header_master[5];
166 uint8_t header_slave[5] = { READY_NOW, SANITY_CHECK,
167 0x00, 0x00, 0x00 };
168 struct net_buf *buf = NULL;
169
170 union {
171 struct bt_hci_cmd_hdr *cmd_hdr;
172 struct bt_hci_acl_hdr *acl_hdr;
173 } hci_hdr;
174 hci_hdr.cmd_hdr = (struct bt_hci_cmd_hdr *)&rxmsg[1];
175 int ret;
176
177 ARG_UNUSED(p1);
178 ARG_UNUSED(p2);
179 ARG_UNUSED(p3);
180
181 (void)memset(txmsg, 0xFF, SPI_MAX_MSG_LEN);
182
183 while (1) {
184 tx.buf = header_slave;
185 tx.len = 5;
186 rx.buf = header_master;
187 rx.len = 5;
188
189 do {
190 ret = spi_transceive(spi_hci_dev, &spi_cfg,
191 &tx_bufs, &rx_bufs);
192 if (ret < 0) {
193 LOG_ERR("SPI transceive error: %d", ret);
194 }
195 } while ((header_master[STATUS_HEADER_READY] != SPI_READ) &&
196 (header_master[STATUS_HEADER_READY] != SPI_WRITE));
197
198 if (header_master[STATUS_HEADER_READY] == SPI_READ) {
199 /* Unblock the spi tx thread and wait for it */
200 k_sem_give(&sem_spi_tx);
201 k_sem_take(&sem_spi_rx, K_FOREVER);
202 continue;
203 }
204
205 tx.buf = txmsg;
206 tx.len = SPI_MAX_MSG_LEN;
207 rx.buf = rxmsg;
208 rx.len = SPI_MAX_MSG_LEN;
209
210 /* Receiving data from the SPI Host */
211 ret = spi_transceive(spi_hci_dev, &spi_cfg,
212 &tx_bufs, &rx_bufs);
213 if (ret < 0) {
214 LOG_ERR("SPI transceive error: %d", ret);
215 continue;
216 }
217
218 switch (rxmsg[PACKET_TYPE]) {
219 case HCI_CMD:
220 buf = bt_buf_get_tx(BT_BUF_CMD, K_NO_WAIT,
221 hci_hdr.cmd_hdr,
222 sizeof(*hci_hdr.cmd_hdr));
223 if (buf) {
224 net_buf_add_mem(buf, &rxmsg[4],
225 hci_hdr.cmd_hdr->param_len);
226 } else {
227 LOG_ERR("No available command buffers!");
228 continue;
229 }
230 break;
231 case HCI_ACL:
232 buf = bt_buf_get_tx(BT_BUF_ACL_OUT, K_NO_WAIT,
233 hci_hdr.acl_hdr,
234 sizeof(*hci_hdr.acl_hdr));
235 if (buf) {
236 net_buf_add_mem(buf, &rxmsg[5],
237 sys_le16_to_cpu(hci_hdr.acl_hdr->len));
238 } else {
239 LOG_ERR("No available ACL buffers!");
240 continue;
241 }
242 break;
243 default:
244 LOG_ERR("Unknown BT HCI buf type");
245 continue;
246 }
247
248 LOG_DBG("buf %p type %u len %u",
249 buf, bt_buf_get_type(buf), buf->len);
250
251 ret = bt_send(buf);
252 if (ret) {
253 LOG_ERR("Unable to send (ret %d)", ret);
254 net_buf_unref(buf);
255 }
256
257 /* Make sure other threads get a chance to run */
258 k_yield();
259 }
260 }
261
hci_spi_init(void)262 static int hci_spi_init(void)
263 {
264
265 LOG_DBG("");
266
267 if (!device_is_ready(spi_hci_dev)) {
268 LOG_ERR("SPI bus %s is not ready", spi_hci_dev->name);
269 return -EINVAL;
270 }
271
272 if (!gpio_is_ready_dt(&irq)) {
273 LOG_ERR("IRQ GPIO port %s is not ready", irq.port->name);
274 return -EINVAL;
275 }
276 gpio_pin_configure_dt(&irq, GPIO_OUTPUT_INACTIVE);
277
278 return 0;
279 }
280
281 SYS_INIT(hci_spi_init, APPLICATION, CONFIG_KERNEL_INIT_PRIORITY_DEVICE);
282
main(void)283 int main(void)
284 {
285 static K_FIFO_DEFINE(rx_queue);
286 struct bt_hci_evt_hdr *evt_hdr;
287 struct net_buf *buf;
288 k_tid_t tx_id;
289 int err;
290
291 LOG_DBG("Start");
292
293 err = bt_enable_raw(&rx_queue);
294 if (err) {
295 LOG_ERR("bt_enable_raw: %d; aborting", err);
296 return 0;
297 }
298
299 /* Spawn the TX thread, which feeds cmds and data to the controller */
300 tx_id = k_thread_create(&bt_tx_thread_data, bt_tx_thread_stack,
301 K_THREAD_STACK_SIZEOF(bt_tx_thread_stack),
302 bt_tx_thread, NULL, NULL, NULL, K_PRIO_COOP(7),
303 0, K_NO_WAIT);
304 k_thread_name_set(&bt_tx_thread_data, "bt_tx_thread");
305
306 /* Send a vendor event to announce that the slave is initialized */
307 buf = bt_buf_get_rx(BT_BUF_EVT, K_FOREVER);
308 evt_hdr = net_buf_add(buf, sizeof(*evt_hdr));
309 evt_hdr->evt = BT_HCI_EVT_VENDOR;
310 evt_hdr->len = 2U;
311 net_buf_add_le16(buf, EVT_BLUE_INITIALIZED);
312 err = spi_send(buf);
313 if (err) {
314 LOG_ERR("can't send initialization event; aborting");
315 k_thread_abort(tx_id);
316 return 0;
317 }
318
319 while (1) {
320 buf = net_buf_get(&rx_queue, K_FOREVER);
321 err = spi_send(buf);
322 if (err) {
323 LOG_ERR("Failed to send");
324 }
325 /* Ensure that the IRQ line is de-asserted for some minimum
326 * duration between buffers, so that the HCI controller has
327 * time to observe the edge.
328 */
329 k_sleep(K_TICKS(1));
330 }
331 return 0;
332 }
333
